Electrical weft detector for cam box looms



Dec. l, 1931. w. WAKEFIELD I 1,834,360

ELECTRICAL WEFT DETECTOR FOR CAM BOX LOOMS Filed April 16, 1951{Sheets-Sheet 1 W. H. WAKEFIELD 02? para; 1

ELECTRICAL WEFT DETECTOR FOR CAM BOX LOOMS Filed April 16, 1951 2.Sheets-Sheet 2 Patented 'Dec. 1, 1931 UNITED STATES PATENT OFFICE WALTERH. WAKEFIELD, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO CROMPTON &KNOWLES LOOMI WORKS, OF WORCESTER, MASSACHUSETTS, A CORPORATION OFMASSACHUSETTS ELECTRICAL WEFT DETECTOR FOR CAM BOX IlOOMS Applicationfiled April 16,

Thisinvention relates to improvements in electrical weft detectors forcam box looms and it is the general object of the invention to providesimple means whereby a selection may be made as to which of theplurality of circuits shall be closable at weft exhaustion.

Certain classes of goods such as serge are woven on a so-called fillingmixing loom which has two shuttle boxes at one end of the loom and asingle box at the other end,

being inup position for two picks and then in down position for theother two picks of the cycle.

Weft detection ordinarily takes place at front center with the boxesmoved half way between their extreme vertical positions. When anelectrical detector is employed for each shuttle the contact resultingfrom weft exhaustion is made when the lay is in its forward position,but both detectors can indicate, although but one of the shuttles can beactive on the pick immediately following indication. As a result'it isnecessary to be able to determine which of the two detectors shall be incontrol of the loom. It is an important object of my present inventionto provide a selector which shall be operated by the cam to antici atethe circuit of the shut- 1931. Serial ms. 530,598.

mate position. It is a further object of my present invention to providea circuit closer which shall be positioned by one dwell while the leverfor the boxes is just leaving the 1 With these and other objects in viewwhich 'Will appear as the description proceeds, my invention resides inthe combination and arrangement of parts hereinafter described and setforth in the claims.

In the accompanying drawings, wherein a'convenient embodiment of myinvention is set forth,

Fig. 1 is an end elevation of a loom having my invention appliedthereto,

Fig. 2 is a diagrammatic showing of the circuits and cam, together withthe levers which areccontrolled by the cam, and e Fig. 3 is adiagrammatic view of the circuits containing the loom controller andshowing the manner of selection which circuit shall be operative at anygiven time.

In the drawings I have shown a loom frame 10 havin a lay 11 movable backand forth by means of connectors 12. A gang of shuttle boxes 13 havingupper and lower cells 14 and 15, respectively, to receive shuttles Sand, S, respectively, are mounted on the top of a box rod 16. The latteris connected to the forward end of a box lever 17 pivoted at 18 andhaving driving connection with a box cam 19. The latter is secured to aspur shaft 20 which is in turn connected by a 2 to 1 gearing to a bottomshaft 21 of the loom. The latter makes one revolution for two picks ofthe loom, so that the cam will require four picks for one completerevolution.

The camhas a high dwell 22 and a low dwell 23, these dwells beingconnected by inclines which are set forth herein as at 24 and 25. Thecam .moves in the direction of arrow and as shown therein the lever 17is in the position corresponding to front center of the lay with theboxes moved half way between bottom and top positions going up. 'Inother words, the lay race R is half way between the floors of the boxcells 14 and 15.,

, position to the other.

In the operation of the loom each of the cells of the gang of boxes willbe in active position during the greater part of two successive picksand during the remainder of the pair of picks will be shifting from oneThe boxes will maintain their new position for approximately a pick anda half, and then move again to shift, so that the effect of the cam isto permit each shuttle to be in action for each of two successive picksonly, the shuttles alternating to mix the filling. Y

The upper and lower detectors 30 and 31, respectively, are preferably ofthe electrical type, each having a pair of contact fingers 32 and 33,respectively. The detectors are mounted on a slide 34 which is guided bya fixed frame 35. The slide 34 is attached to a lifter rod 36 the lowerend of which is pivotally connected as at 37 to the box lifter rod 16.As the boxes rise and fall the detectors move vertically with them sothat each detector enters its box on each forward beat of the loom. Itis not deemed necessary to illustrate the shuttle circuit or the formofcircuit closure located within the shuttle, as it is sufficient forpresent purposes to state that when weft is absent in either shuttle thecontact fingers 32 and 33 corresponding thereto will be in electricalcontact with each other. The fingers are insulated from the loom frameand from each other.

It is to be understood that the detector fingers 32 and 33 will beconnected electrically while the lay is in its front position and at atime when the boxes are at an intermediate position on detecting beatsof the loom. Because of the fact that the detectors will close theircircuitsto be described at substantially the same time in the cycle ofthe loom and with the boxes in approximately the same position it isnecessary to provide some means for determining which of the detectorsunder these conditions shall be operative. This result ll achieve bymeans operated by the cam. I

-A lever 40 pivoted at 41 has a roll 42 to engage the various surfacesof the cam, said lever being mounted on a grounded support and having aselector end 43 which is movable from one to the other of two contactbuttons 44 and 45, respectively, being in contact with but one at atime. The roll 42 is preferably placed at an angular distance rseaeeothe selector lever approximately half a pick in advance of itsengagement with the box lever. In view of the fact that the inclinedparts of the cams areof a length corresponding to half a pick the resultis that as a shift of the boxes is about to take place the selectorlever will be in engagement with the dwell moving toward and therefordetermining the new position of the box lever.

Referring to Fig. 2 it will be seen that the high dwell 22 which ismoving toward the box lever is already in engagement with the selectorlever and has moved the same into engagement with the contact 45.Inasmuch as the box lever is raising the boxes under these conditions itis necessary to connect button 45 electrically with the detector of thebottom or lower detector 31. Under the assumed condition, it is theshuttle correspond ing to this detector whic will be active when theboxes are raised. In like manner during the second pick to follow, whenthe box lever is still in contact with the high dwell 22, the roll 42will have moved down incline 25 and will be in engagement with the lowdwell 23, thereby efiecting movement of the selector lever intoengagement with the button 44. The latter is connected to the topdetector 30.

When the parts are in the position shown diagrammatically in Fig. 2 andweft is exhausted in the bottom shuttle, current will flow through thefollowing circuit: ground G, wire 50, selector lever 40,--arm 43, button45, wire 51, finger 33 of the lower detector 31, the other finger 32 ofsaid detector, Wire 52, source of electrical energy P, wire 53,electromagnetic device E, wire 54, and back to ground G. Current flowingin this device will energize device E which will act upon its armatureor core actuator 55 and by at-- t'racting the latter, or producing achange in its position, will set mechanism not shown to bring about achange in the operation of the loom. It is not deemed necessary hereinto show a device for effecting such a change, as these mechanisms arewell-known, and itis considered sufiicient to state herein that movingpart 55 due to a change in the magnetic field of device E may result inweft replenishment, or in loomstoppage.

When the parts are in the reversed position with the box lever movingdown along incline 25, the selector lever will have previ-.. ously beenpositioned by dwell 23 and moved by spring 38 to have engagement withthe button 44. If, under these conditions, Weft I should be absent inthe upper shuttle, current will flow through the following circuit:ground G, wire 50, selector lever arm 43, button 44, wire 60, fingers 33and 32 01 the upper detector, wire 52, source of electric power P, wire53, electro-magnetic device E, and wire 54, back to ground G. Currentflowing in this circuit will likewise energize electromagnetic devices Ewith the same result as that described in connection with the firstcircuit traced.

By reason of the structure set forth herein I am enabled to determinewhich circuit can be closed by its weft detector prior to the com- Ipletion ofthe movement of the boxes, and

more particularly while the lay is in its foremost position, the timewhen the detector ordinarily operates. In the type of loom to which thisinvention more particularly relates the sequence of box movements isfixed and I am therefore able to use the cam surface or its equivalentwhich determines the movements of the boxes for the purpose of selectingthe circuit which corresponds to the shuttle that is next going to beactive.

Even though both shuttles should be exhausted at the same time therewill be but one circuit closed, and that will correspond to the shuttlethat is moving into action. As in usual constructions of Weft detectors,the latter will not engage the shuttles at the beginning or ending ofthe box lift, but will be in engagement with the. weft for acomparatively short time when the boxes are half shifted with the lay atfront center, this fact together with the relation of the levers to thecam surfaces making it impossible to close a circuit on an exhaustedshuttle which has just entered one of the shifting boxes and is movingout of active po'sition.

From the foregoing it will be seen that I have provided two circuits forthe electrical weft detectors of a cam box loom and determine whichdetector can be electrically connected to the electromagneticdeviceprior to complete movement of the boxes and whilev the detectorsare in contactwith the weft.

Because of the fixed order in which the shuttles move the selector leveris always in prop er relation relatively to the shuttle which is next tobecome active and for this reason there is no opportunity for themagazine to replenish the. wrong shuttle. have shown electrical feelersto closecircuits internal relatively to the shuttles, yet I do not wishto be limited to. this arrangement, and certain features of my inventionwill operate regardless of the type of feeler used,

. so long as a circuit will be closed by the de-' tector when exhaustionof weft occurs. -Any other form of detector may be used, to closecircuits at detection.

Having thus described my invention it will be seen that changes andmodifications may be made therein by those skilled in the art withoutdeparting from the spirit and scope of the invention and I do not wishto be limited to the details herein disclosed, but what I claim is: I

1. In weft detecting mechanism for a box loom having a pair of shiftingboxes, a cam to mbve each box in active position for two successlvepicks and then out of action for to move each Although I moving with theboxes as the latter shift, a

pair of 'detector electric circuits, one for each detector, anelectromagnetic device common to the' circuits effective when energizedto cause a change in the operation of the loom, and av selector to beelectrically connected to each circuit, one at a time, to determinewhich detector circuit shall be operative, said selector being moved bythe cam in advance of movement of the boxes.

2. In weft detecting mechanism for a box loom having a air of shiftingboxes, a cam ox into active position for two successive picks and thenout of action for two successive picks, a pair of electrical weftdetectors, one for each box, the detectors moving with the boxes as thelatter shift, a pair of detector electric circuits, one

for each-detector, an electromagnetic device common to the detectorcircuits effective when energized to cause a change in the operation ofthe loom, a selector to determine which is of the detecting circuitsshall be operative, said selector movable into electrical engagementwith but one detector circuit ing with the boxes as the latter shift, apair of electric circuits, one for each detector, an

electromagnetic device common to the circuits effective when energizedto cause a change'in the operation of the loom, the cam having high andlow dwells separated by inclined faces which are effective to shift theboxes, and a selector to determine which of the detector circuits shallbe operative, the selector being engaged by one of the dwells of the camwhile the other dwell is still operatively related to the boxes.

4. In weft detecting mechanism for a box detectors, one for each box,the detectors:

moving with the boxes as the latter shift, a pair of electriccircuits,'one for each detector, an electromagnetic device common to thecircuits effective when energized to cause a change in the operation ofthe loom, the cam having high and lowdwells separated by inclined faceswhich are effective to shift the boxes, and a selector to determinewhich of the detector circuits shall be operative, the

selector being engaged by one of the dwells iso of the cam before saiddwell becomes operatively related to the boxes. 1

5. In weft detecting mechanism for a box loom having a pair of shiftingboxes, a cam to move each box into active position for two successivepicks and then out of action for two successive picks, an electricalWeft detector for each box, the detectors moving with the boxes as thelatter shift, an electric circuit for each detector, an electromagneticdevice common to the circuits to cause a change in the operation of theloom, the cam having highv and low dwells separated by inclined faceswhich are efiective to shift the boxes, a box lever to engage the camand transmit a force from the latter to the boxes, and a selector tohave electrical engagement one circuit at a time, said selector havingengagement with the cam at a point in advance of the point of engagementbetween the lever and the cam with respect to the direction of movementof the latter.

6. In weft detecting mechanism for a drop box loom having a pair of dropboxes, a cam to move each box 1nto active position for two success vepicks and then out of action for two successive picks, an electricalweft detector for each box, the detectors moving with the'boxes as thelatter shift, an electric circuit for each detector, an electromagneticdevice common to the circuits to cause a change in the operation of theloom, the cam having high and low dwells separated by inclined faceswhich are effective to shift the boxes, a box lever to engage the camandtransmitting a force from the latter to the boxes, a selector to beelectrically connected to the circuits one at a time, said selector andbox lifting lever being in contact with portions of the cam of differentlevels when the deteeters are in detecting position, the selector beingin advance of the lever with respect to the direction of movement of thecam.

In testimony whereof I have hereunto af-k fixed my signature.

WALTER H, WAKEFIELD.

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